A long-acting antimicrobial medical oil emulsion belongs to a long-acting antimicrobial medical dosage form and comprises aqueous phase with antimicrobial medicine, oil phase, emulsifier and stabilizer, wherein the oil phase adopts 7# or 15# of white oil, the aqueous phase emulsifier is Tween-80, the oil phase emulsifier is Span-80; and the aqueous phase is covered by oil to be dispersed in the oil phase. The dosage form can fully control the release of the antimicrobial action of active ingredients of the antimicrobial medicine, save the breeding cost, reduce the environmental pollution, and the like; and the dosage form is suitable for the preparation of active ingredients of various water-soluble or oil-soluble antimicrobial medicines. The invention provides the corresponding technical support for healthy raise in aspects of chemoprophylaxis and treatment of diseases.